24yrold&86conv

So I finally got all my ball-joints, tie-rods, and bushings in front and back replaced on saturday. I drive it home and it drives the best I've ever had it, until later that night when I go to head home and after just getting on the highway the engine just stops running. The dash and all lights stayed on but the engine just died and nothing happened when giving gas, so I pull to the side off the road and try starting it. It tries to start but doesn't actually get running at all, had to get it towed to mechanic by my house. In the morning I thought it was just the fuel-pump since it tries turning over, but the fuel-pump is fine. So i hand it over to the mechanic and he thought it was the distributor but when we replaced it it still didn't start, so he checked the compression and said it doesn't have any. He thinks the timing chain broke. Any ways to test what it is? If the timing chain broke wouldn't it break valves and rods in the engine?

ghoastrider1

rest easy on the valves. The 86 corvette engine is NOT a valve interfer engine. The timming chain breaks, it simply stops running. replace it(and the gear) , and all is fine inside. 90% of the time your vette stops running is because of the coil or fuel pump. Just put a timming light on to test. Easy to tell if the thing jumped time.

pcolt94

Pull the distributor cap off and crank the engine. Watch to see if the rotor is turning. If it is not, it could be the chain. If it is, then chain is OK since the distributor runs off the cam and the cam is obviously turning.

Purple92

I'd suggest pulling a valve cover off and seeing if any of the rocker arms move when cranking. If the distributor isn't turning when cranking - it could be the distributor gear - if none of the rocker arms are moving - you know it's a timing chain.

bjankuski

Are you sure about this? I have never seen a SBC that breaks a timing chain and does not crash the valves. The valve lift on a 1986 is low at .415 but I do not believe there will be that much piston to valve clearance at TDC. My assumption is the valves and pushrods will be bent on a few cylinders.

SJW

If the engine suddenly has no compression, the most likely failure was the timing chain. A leakdown test can reveal bent valves.

Live well,

SJW

DanielRicany

Remove the rockers arms to do a leak down test. Easier than pulling off the timing covers to turn the cam.

ghoastrider1

I have never encountered a broken timing chain. Seen many a striped gear or a streched chain, but not one broken. Timing light is THE easest way..and cheapest, to find out of the timing is off either due to a bad chain/gear or a bad gear on the dist. Bottom line is., it tells if the timing is the problem or not. Why rip off a valve cover?

24yrold&86conv

I will see if the mechanic has a gauge to do the leak down test. At this point he's just thinking that a valve is bent due to 0 compression.

Man oh man, how much is this all going to cost? And let me remind you I live in NJ right by NYC...

24yrold&86conv

Can this be done if the engine doesn't run? The mechanic told me this yesterday, "we looked down the oil cap on the valve cover to see if the rocker arms move when we try to crank and they didn't, therefore its the timing chain".

Sounds like it's definitely the timing chain, I ordered the parts already and am just hoping there's no bent rods or valves since everyone is skeptical of it being a true non-interference engine.

Joe C

same here. I'm NOT saying it can't happen, but in 40+ years, I've never seen it on a SBC. keep us posted, and when you find the problem, and it is a broken chain, post a pic. I'd like to see one. good luck on the repairs....

s carter

I would not worry about the thought of a bent valve do to the chain beaking, as far as I rember you do not have a self destructive motor. I would be surprized unless you were running the car way to hard and you floated a valve, if that's the case any thing goes after that

DanielRicany

I broke a cloyes single non roller timing chain and stripped the crank sprocket on my '85. It bent 3 valves. Cost me about $600 to fix it myself I think. Needed to get 3 new valves, valve job on both heads, new chain set, timing cover, timing cover gasket, water pump gaskets, intake gaskets, header gaskets, head gaskets and probably a few other small things. My car is modified though. Yours will probably cost close to what mine did if it bent any valves. If the chain popped and took out a few valves, the cost in fixing the motor would probably be around the price of a used motor. This includes labor for both jobs.

It's gonna cost a lot if you don't do it yourself.

24yrold&86conv

I don't know how to do any of this. FML

pcolt94

No offense, but do you know what to look for. I hate to see someone pull the wool over your eyes. That why I thought looking at the rotor was a pretty straight forward visual test that would be a clear observation.

mtwoolford

I can only say that it happened to me twice, on a Ford and a Chevy. The distributor gear, that meshes with the gear on the cam, is only pined onto the distributor with a small, and I might say, brittle, roll pin...if it fails the distributor gear simply spins on the distributor shaft and the distributor doesn't rotate , or if it does rotate, it only rotates sporadically and out of time with the engine, hence the "it tries to start" symptoms and the oil pump, which is driven by the distributor shaft, doesn't turn / pump either. Just pull the distributor. If it is a broken pin, its a two dollar fix...probably the only two dollar fix on a corvette

Cliff Harris

It only takes a few minutes to pull the distributor cap and it's easy to put back together compared to some of the other suggestions offered.

Mark8801

You need a different mechanic. He replaces a distributor because he thinks that's what the problem is.?.? I can see maybe having to make a educated guess on an intermittent problem but when the thing flat out doesn't start at all? It's not that hard of a problem to diagnose. Run from that dude as fast as you can!

ghoastrider1

this has happened to me also. once. in my old 67 ford pick up (6 cyl) The last 4 post offer decent advice. As far as pulling the dist cap.. should be first on the list of where to look. Don't you have any friends that know something about cars? Any vette forum members live close by?

24yrold&86conv

I have no idea about any good mechanics or members out here, I moved here for a job. I am getting AAA and having it towed from the mechanic by my house to the only mechanic I trust which is 50 miles away. He did the whole suspension for a reasonable price and seems to be a straight up honest guy.